Anthryl substituted acrolein compounds

ABSTRACT

AND THEIR SALTS ARE USEFUL AS INTERMEDIATE PRODUCTS FOR THE MANUFACTURE OF VALUABLE COMPOUNDS, ESPECIALLY PHARMACEUTICALLY ACTIVE COMPOUNDS. 9-(3-Oxo-1-propenyl)-9,10-dihydro-9,10-ethano-anthracenes possessing a nucleus of the formula

United States Patent [111 3,903,170

Beck et al. Sept. 2, 1975 ANTHRYL SUBSTITUTED ACROLEIN [56] References Cited COMPOUNDS UNITED STATES PATENTS [75] Inventors: Dieter Beck, Basel; Raymond 3,399,201 8/1968 Schmidt et al 260/599 X Bernasconi Oberwil Basel Land; Schmidt Ct al Karl Schenker, Binningen; Max Wilhelm, Allschwil, n f Primary ExaminerBernard Helfin Switzerland Attorney, Agent, or Firm-Joseph G. Kolodny; Theodore O. Groeger; John J. Maitner [73] Ass1gnee: Clba-Gelgy Corporation, Ardsley,

NY 57 ABSTRACT [22] Filed: Jan. 14, 1974 9-(3-Oxo-l-propenyl)-9,l0-dihydro-9,l0- [71] AP 1 No 432 927 ethano-anthracenes possessing a nucleus of the h p formula Related US. Application Data [62] Division of Ser. No. 225,614, Feb. 11, 1972. 7 8 9 1 2 [30] Foreign Application Priority Data 3 (I) Feb. 23. l97l Switzerland 2576/71 Jan. 17. 1972 Switzerland 667/72 5 4 l 52] U S Cl 260/599 260/600 and their salts are useful as intermediate products for v [51] 6 47/56 the manufacture of valuable compounds, especially [58] Field of Search 260/599, 600 Pharmaceutically active compounds- 5 Claims, N0 Drawings 1 ANTHRYL SUBSTITUTED ACROLEIN COMPOUNDS This application is a division of application Ser. No. 225,614, filed Feb. 11', 1972.

SUMMARY OF THE INVENTION The present invention relates to cyclic compounds and a process for their manufacture.

The present invention provides 9-(3-oxo-lpropenyl )-9, l O-dihydro-9, l (l-ethano-anthracenes possessing a nucleus of the formula 1 The l-propenyl radical present as a substituent in the 9-position of the anthracene nucleus is preferably only substituted by the oxo group, but may also be further substituted by lower alkyl radicals, for example, those mentioned below, especially by methyl or ethyl radicals. The l.-propenyl radical preferably does not possess more than one such lower alkyl radical as a substituent.

The term *lower" is used here and throughout the specification to denote such alkyl groups and other aliphatic radicals, for example, alkenyl, alkoxy and alkanoyl groups. as contain up to 7, and preferably not more than 4 carbonatoms.

Lower alkyl radicals are accordingly methyl, ethyl, propyl and isopropyl radicals, and straight or branched chain butyl, pentyl, hexyl or heptyl radicals bonded in any desired position.

in the compounds of the invention, the positions 11 and/or 12 may be substituted by lower alkyl radicals, for example, those mentioned, but the positions 11 and 12 are preferably unsubstituted.

The compounds of the invention are preferably un substituted in positions 1 to 8 of the anthracene ring but may carry substituents in these positions, for example, substituents selected from lower alkyl, lower alkoxy, lower alkenyloxy, lower alkylmercapto, lower alkylsulphonyl, lower alkanoyl, nitro, and amino groups, but preferably trifluoromethyl groups or halogen atoms, for example, fluorine, bromine and iodine and particularly chlorine atoms; as alkyl radicals, methyl, ethyl, propyl, isopropyl, butyl iso-butyl and tertiary butyl radicals should be mentioned especially; as alkoxy or alkenyloxy groups methoxy, ethoxy, allyloxy and methylenedioxy groups should be mentioned; as alkymercapto groups methylmercapto and ethylmercapto groups should be mentioned; and as alkanoyl radicals acetyl, propionyl and butyryl radicals should above all be mentioned. The substitution in positions 1 to 8 may be multiple, but is preferably double, and advantageously single. Preferred positions of substituents are the 3-position and especially the 2-position,

The compounds of the invention may be substituted in the l()-position by a lower alkyl radical, for example, one of those mentioned above, or a halogen atom, above all a chlorine atom, butthis position is preferably unsubstituted.

The invention also provides functional derivatives of the compounds of the invention, for example, their acctals, hydrates, oximes, hydrazones, semicarbazones or bisulphite addition products, also form a subject of the invention.

The compounds of the invention are useful as intermediate products for the manufacture of valuable compounds, especially pharmaceutically active com pounds, for example, the psychotropically active compound 9-('y-aminopropyl)-9, l O-dihydro-9, l O-ethano anthracenes (described in US. Pat. No. 3,399,201 which can be formed, for example by the reaction of the new compounds prepared according to the procedure described in this specification with a primary or secondary amine and subsequent hydrogenation of the formed azomethine or hydroxyamino-compound.

The compounds of the invention which are particularly useful as intermediates are compounds of the formula la in which n and In each denote an integer from O to 4, (n m) preferably being not greater than 3, nl preferably representing 0 and n for example, representing 2, but advantageously l and especially 0, the radicals R which may be the same or different, each represents a radical selected from the groups mentioned above as substituents of the positions 1 to 8, and a single substituent R is preferably in the 3-position or especially in the 2-position, R denotes one of the groups mentioned above as substituents of the l0-position or especially denotes a hydrogen atom, the symbols R R,,' and R,,", which may be the same or different, each represents a lower alkyl radical, for example, those mentioned, for example, ethyl groups, preferably methyl groups, or especially represents a hydrogen atom, with preferably at most one of the three symbols being dif ferent from hydrogen, and Ae denotes a 1,2-ethylene radical which is substituted in the l-position and/or 2- position by a lower alkyl radical, for example, by one of those mentioned for example, a methyl, ethyl, propyl or isopropyl radical, but is preferably unsubstituted.

Particularly important intermediate products are those compounds of the formula Ia, where R denotes lower alkyl, lower alkoxy, trifluoromethyl groups or, preferably, halogen atoms, for example, bromine atoms or especially chlorine atoms, and R denotes a halogen atom, preferably a chlorine atom, or above all a hydrogen atom.

Further compounds which are especially useful are those of the formula 11 CH=CHCHO (III) CH=CH-CHO from which 9-(3-methylaminopropyl)-9,lO-dihydro- 9,lO-ethano-anthracene (see British Patent 1,069,069) can be obtained, for example, by reaction with methylamine and hydrogenation in the presence of palladium on charcoal.

Attempts to manufacture the compounds of the invention starting from the known 9-formyl-9,l0- dihydro-9,lO-ethano-anthracenes by acetalisation, chain lengthening by reaction with vinyl ethyl ether and acid hydrolysis of the product formed, failed. The addition of ethylene which was unsubstituted or loweralkylated to appropriate 3-(9'aathryl)-acrolein compounds appeared unpromising, since participation of the activated double bond of the side chain, as part of a diene system, was to be expected. In fact, the reaction of ethylene with 3-(9-anthryl)-acrolein in dimethylformamide gave a mixture of a large number of compounds.

The present invention also provides a process for the manufacture of a 9-(3-oxo-l-propenyl)'-9,lO-dihydro- 9,10-ethano-anthracene possessing a necleus of the formula which comprises reacting the corresponding 3-(9- anthryU-acrolein with ethylene, which maybe lower allcylated, in the presence of an inert, heat-stable solvein.

Surprisingly, compounds of the invention are obtained in good yield and in a pure form.

As inert, heat-stable solvents, there may be mentioned, for example, hydrocarbons, for example, aliphatic, cycloaliphatic or above all, aromatic hydrocarbons, for example an alkane, or a cyclolkane having a molecular weight of above 80, cycloalkane which may be lower alkylated, for example, methylated, or a xylene, benzene, cumene or, especially, toluene.

Further examples to be mentioned are saturated alcohols, for example, alkanols or cycloalkanols, for example, ethanol or isopropanol; preferably aliphatic nitriles, for example, acetonitrile; carboxylic acids and especially esters thereof, for example, lower alkanecarboxylic acids and their esters, for example ethylacetate, aromatic nitro compounds, for example nitrobenzene and aromatic ethers, for example, diphenyl ether.

The reaction is advantageously carried out under pressure, for example, under a pressure of from 20 to 200, and preferably from to I00, atmospheres, and with warming, for example at a temperature of from 50 to 220, especially at a temperature of from I 50 to 220.

A resulting 9-( 3-oxo-l-propenyl)-9, lO-dihydro-9, 10- ethano-anthracene can be converted into a reactive functional derivative thereof, above all those mentioned, by, for example, adding an alcohol, water, hydroxylamine, hydrazine, semicarbazide or bisulphite, where appropriate with elimination of water. Conversely, the free aldehyde or ketone may be formed from a resulting derivative of this nature, for example, by acid hydrolysis.

The invention also provides a process for the manufacture of a 9-( 3-aminopropyl)- or 9-(3-amino-lpropenyl )-9, l O-dihydro-9, I O-ethanoanthracene which comprises condensing a 9-( 3-oxo-lpropenyl)-9,l0- dihydro-9, l O-ethanoanthracene with an amine and partially or completely hydrogenating the resulting compound.

The invention further provides the 3-(9-anthryl)- acrolein compounds (V) C =CH-CHO =CH-CHO wherein R has the above mentioned meanings and is in the 3-position or is preferably in the 2-position.

Particularly valuable starting products are the compounds of the formula (Vlll) CH==CH-CHO v I II wherein R has the above mentioned meanings.

As already mentioned above, it had proved impossible to manufacture 9-(3-oxo-1-propenyl)-9,l()- dihydro-9, l ()-ethanoanthracenes starting from the corresponding Q-formyl compounds by acetalisation, chain lengthening by reaction with vinyl ethyl ether and acid hydrolysis of the product formed. It was therefore to be expected that the manufacture of the 3-(9-anthryl)- acrolein compounds (V) would be possible only with complicated multi-stage syntheses.

The present invention provides a process for the manufacture of a 3-(9-antryl)-acrolein compound (V) which comprises acetalizing a corresponding 9-formylanthracene compound reacting the acetal with an ethenyl ether or ethenyl ester, for example, a vinyl ether or a vinyl -anthryl)acrolein and decomposing the resulting condensation product IX with an aqueous acid. The yield is good.

The alcoholic component of the acetal is preferably a lower alkanol. for example, propanol, methanol and advantageously ethanol. The acetalisation is, for example, effected with the aid of an ortho-ester, especially with the aid of an ortho-ester ofa lower alkanoic acid, for example. formic acid or acetic acid, preferably by reaction with orthoformic acid triethyl ester. The reaction is appropriately carried out in ,the presence of a catalyst. especially an acid catalyst. for example, boron trifluoride. for example. in the form of boron trifluoridediethyl-etherate, The ethenyl-cther is preferably an ethenyllower alkyl ether. for example, an ethenyl-ethyl ether. for example. vinyl-ethyl ether, and is advantageously only employed in slight excess. An ethenyl ester, particularly such an ester ofa carhoxylic acid. preferably of a lower alkanoic acid, for example vinyl acetate or vinyl formate,,and is advantageously employed only in a slight excess. The decomposition of the resulting alkoxy acetals can appropriately be effected in the presence of a solvent, especially an or ganic solvent, for example, a lower alkanol, for example, isopropanol. As the acid, any desired inorganic or organic acid, for example a fairly strong or preferably a strong acid, can be used, for example a mineral acid, for example perchloric acid, sulphuric acid or especially hydrochloric acid; or a carboxylic acid, for example, a lower alkanecarboxylic acid, for example, acetic acid; or an organic sulphonic acid, for example, an alkanesulphonic acid, for example, methanesulphonic acid; or an arylsulphonic acid, for example, p-toluenesulphonic acid or p-bromobenzenesulphonic acid.

A resulting 3-(9-anthryl)-acrolein compound (V) can be converted into a reactive functional derivative thereof, especially into those indicated, by adding for example, an alcohol, water, hydroxylamine, hydrazine, semicarbazide or bisulphite, where'appropriate with elimination of water. Conversely, the free aldehyde or detone can be formed from resulting derivatives of this nature, for example, by acid hydrolysis.

The 3-(9-anthryl)-acrolein compounds V can also serve for the synthesis of the initially mentioned 9-(3- iminol -propenyl )-9, l O-dihydro-9, l O-ethanoanthracenes by a different route than via the 9-(3 -oxol-propenyl)-9,lO-dihydro-9,10ethano-anthracenes which by themselves can serve as starting materials for the above mentioned 9-(3-amino-propyl)-9,l0- dihydro-9,IO-ethano-anthracenes. Thus, the invention provides a process for the manufacture of a 9-(3-iminol -propenyl )-9, l O-dihydro-9, l O-ethano-anthracene which comprises condensing a 3-(9-anthryl)-acrolein compound V with a suitable amine and reacting the resulting Schiffs base with an ethylene which may be unsubstituted or lower alkylated.

The invention further provides a process for the manufacture of a 9(3-oxo-l-propenyl)-9,10-dihydro- 9,l()ethanoanthracene wherein the process for preparing a 3-( 9anthryl)-acrolein compound V from a corresponding 9-formyl-anthracene and the conversion of the acrolein compound to a 9-(3-oxo-l-propenyl)- 9,l()-dihydro-9,lO-ethano-anthracene are carried out in succession, that is to say an appropriate 9-formylanthracene compound is acetalized, the acetal is reacted with an ethenyl-ether or ethenyl-ester, the resulting condensation product IX is decomposed with an aqueous acid and the resulting 3-(9-anthryl)-acrolein compound is reacted with ethylene which may be lower alkylated in the presence of inert heat-stable solvents.

The following Examples illustrate the inven ion.

EXAMPLE 1 0.8 ml of BF;,diethyl-etherate is added to 137.1 g of orthoformic acid triethyl ester, and H348 g of anthracene-9-aldehyde are then added in several portions, whilst stirring. The resulting yellow paste is warmed to 4()-45C, whereby a viscous brown-red solution is gradually produced. After 2 hours, cooling of the contents of the flask is started and at the same time 63.4 g of ethyl vinyl other are added dropwise at such a speed that the temperature of the reaction mixture does not exceed 209C. After 2 hours, 161 ml of isopropanol and 24 ml of 2N hydrochloric acid are added and the mixture is heated under reflux for 8 hours. After about l2 hours the product already starts to crystallise nol. and the"3-(Q-anthryl)-acrolein thus obtained, of 5 the formula is dried forjl2 hours at 80 mm Hg/80C in a vacuum cabinet, until it reaches constant weight. The substance is golden yellow and melts at l72l 74C, and after one recrystallisation from chloroform-ethyl acetate it melts at l74l75C. The yield is 171 g (92 percent of theory).

EXAMPLE 2 "232 g l .0 mol) of 3-(9-anthryl)-acrolein and 1,000 ml-of toluene are heated to 170l 80C in a stirred autoclave-Ethylene is injected until the pressure reaches -l00 atmospheres gague and this pressure is maintained for 20hours. The pressure vessel is allowed to cool to 90C, the pressure is carefully released, 20 g of active charcoalare added to the contents of the autoclave and the warm solution is filtered. The filtrate is avaporated to approximately three-fifths of its volume and is then slowly cooled to C. Hereupon 9-(3-oxo-lpropenyl )-9, l 0-dihydro-9, l O-ethano-anthracene of the formula CHO Yet further material can be obtained by concentrating the mother liquor.

EXAMPLE 3 46.8 g of 9,l0-dihydro-9,l0-ethanoanthracene-9- aldehyde in a inixture of 29.6 g of orthoformic acid triethyl ester.-0. ()l g of p-toluenesulphonic acid and 10 ml of absolute alcohol are stirred for 10 hours at room temperature. The clear solution is mixed with 100 ml of ethyl acetate and washed with ml of sodium bicarbonate solution. After drying over potassium carbonate the ethyl acetate is distilled off and the residue is triturated with 30 ml ofabsolutc ethanol. 60.5 g of 9.]-

0-dihydro-9, l O-ethanoanthracene-9-aldehydediethylacetal of the formula and of melting point l25l26C are thus obtained.

30.8 g of 9,l0-dihydro-9,lO-ethanoanthracen-Q- aldehydediethyl acetal are dissolved in 50 ml of chloroform. After adding 0.3 ml of boron trifluoride-etherate, 20 ml of vinyl ethyl ether are added dropwise to this mixture, the temperature constantly being 20C. The dark reaction mixture is washed with sodium bicarbonate solution and water, and after drying over sodium sulphate the solution is evaporated. The residue is triturated with a little ethanol and in two crystallisations 30 g of starting material are recovered. No product resulting from chain lengthening is detectable by thin layer chromatography in the mother liquor which remains.

. EXAMPLE 4 8.2 g of 3-(9-anthryl)-acrolein are dissolved in 150 ml of anhydrous dimethylformamide in a 500 ml pressure autoclave equipped with a magnetic stirrer. Ethylene is injected at room temperature until the pressure reaches 40 atmospheres gauge and the autoclave is then heated to 170C, in the course of which the internal pressure of the autoclave rises to approximately atmospheres gauge. After 20 hours the mixture is worked up. The reaction mixture, which is dark brown in colour, is freed of the solvent in vacuo and the resinous residue (1 1.4 g) is chromatographed on 250 g of silica gel. Fractional elution with benzene yields 0.5 g of a fraction which, based on the infra-red spectrum and on analysis by thin layer chromatography, consists of about half of the desired 9-(3-oxo-l-propenyl)-9,l O- dihydro-9,lO-ethano-anthracene of the formula CHO described in Example 2. The remainder of the reaction mixture consists of at least ten compounds or resins which were not characterised in more detail.

EXAMPLE 5 50 g of 3-(9-anthryl)-acrolein in 400 ml of isopropanol are heated to l70C in a l -1 pressure autoclave equipped with a magnetic stirrer. Ethylene is injected until the pressure reaches atmospheres gauge and the mixture is stirred for a further 20 hours at C. After cooling, the crystalline paste is filtered off, washed with a total of 300 ml of ice-cold isopropanol and subsequently dried to constant weight in vacuo at 80C. 36.5 g (62.571 of theory) of brownish-coloured crystals of 9-( 3-oxo l -propenyl )-9, l O-dihydro- 9,l()ethano-anthracene. of melting point l73l75C.

EXAMPLE 6 50 g of 3-(9-anthryl)-acrolein in 200 ml of acetonitrile are heated to 170C in a 500 ml pressure autoclave equipped with a magnetic stirrer. Ethylene is then injected up to a a total pressure of 80 atmospheres gauge and the mixture is allowed to react for 20 hours at 170-180C, whilst stirring. The contents of the autoclave are cooled to 80C and the darkcoloured reaction solution is treated with 5 g of active charcoal (Norit) and filtered. The filtrate is concentrated to half its original volume at 50 mm Hg and is then cooled to 5C, whereupon 9-( 3-oxol propenyl )-9, 1 0-dihydro-9, l O- ethanoanthracene precipitates as light brown crystals. These are filtered off, thoroughly rinsed with a total of 150 ml of cold toluene and dried to constant weight in vacuo. Yield: 40.1 g 71.5 percent of theory) of brownish-coloured crystals of melting point l73175C, which are identical to the product described in Example 2.

3-[9-(2-Chloro)-anthryl]-acrolein can also be manufactured analogously to the description in Example 1, and 2-chloro-9-(3-oxo-l-propeny1)-9,10-dihydro-9,10- cthano-anthracene can be obtained therefrom by reaction with ethylene as described in this example or in Examples 2 or 5.

EXAMPLE 7 Gaseous methylamine is introduced into a suspension of 26.0 g 9-(3-oxo-1-propenyl)-9,l0-dihydro-9,l0- ethano-anthracene in 200 ml of methanol, whilst stirring. The aldehyde dissolves whilst the mixture becomes warm. The temperature of the reaction mixture rises to 50-55C over the course of a few minutes. As soon as the solution becomes strongly-alkaline (tested with moist indicator paper), the introduction of methylamine is stopped and the solution is left to stand for 30 minutes. On slowly adding 100 ml of water, 9-(3 methyliminol -propenyl )-9, l 0-dihydro-9, 1 (l-ethanoanthracene of the formula NCH precipitates in the form of crystals. The mixture is cooled to 10C and suction-filtered. and 26.2 g of colourless crystals of melting point l28129C are thus obtained.

EXAMPLE 8 A mixture of l 1.6 of 3-(9anthryl )-acrolein and 9.1 g of 33 percent strength ethanolic methylamine in 80 ml of absolute ethanol is stirred for minutes and at the same time gradually warmed to 40C. The clear, brown-yellow solution is cooled to 0C, whereupon dark yellow crystals separate out. These are filtered off and recrystallised from 15 ml of isopropanol and 5 ml 10 of ethyl acetate. 9-(3-Methylimino-l-propenyl)- anthracene of the formula is thus obtained as yellow needles of melting point 122.5-124.5C.

EXAMPLE 9 mixture is cooled and evaporated in vacuo. Crude 9-(3 methyl-imino-1-propenyl)-9,l0-dihydro-9, lO-ethanoanthracene of the formula CH=N CH is thus obtained as a brownish amorphous mass.

A sample is crystallised from methanol and recrystallised. The colourless crystals, of melting point 128129C, are identical in every respect with those described in Example 7.

EXAMPLE 10 To 1 37.1 g ethyl orthoformate' are added 0.8 ml BF etherate and then with stirring 164.8 g anthracene-9- aldehyde in several portions. The resulting yellow paste is heated to 4045 whereby slowly a viscous brownred solution results. After 2 hours, the reaction mixture is cooled down and simultaneously dropwise 81.5 ml vinyl acetate is added. The resulting mixture is heated with stirring at 60 for 10 hours. Then 161 ml isopropanol and 24 ml 2N hydrochloric acid are added After the mixture is refluxed for 8 hours. After cooling to 5, the yellow, fine crystals are filtered off by suction, washed twice with ml portions of isopropanol, once with 80 ml of water and once more with 80 ml of isopropanol and sucked dry. The obtained product is a mixture of anthracene-9aldehyde and the desired 3-(9-anthryl)- acrolein (ratio about 2: 1) which can be separated from this mixture by a chromatography on alumina (activity 2). it melts then at l7()173 and after one recrystallization from chloroformethyl acetate at 173174. It is in every respect identical with the product described in Example 1.

' EXAMPLE 1 1 232 g (1.0 M01) 3-(9-anthryl)-acrolein in 1000 ml ethyl acetate are heated in an autoclave provided with a stirrer to '170l 80. 100 atmospheres gauge of ethylene are injected hot and the mixture is allowed to remain at this temperature and pressure for 20 hours. After cooling to 90, the autoclave is opened, the content treated with 20 g of activated carbon and filtered while still warm. The filtrate is concentrated to about half its volume and then slowly cooled to During this procedure, the 9-(3-oxo-l-propenyl)-9,l0-dihydro- 9,10-ethaho-anthracene crystallizes out and is filtered off by suction and washed with a total of 400 ml ethyl acetate. The resultingbrownish crystals are dried to constant weight at 80 Torr and 100 (15 hours). The m.p. of l7 4.1 75 of this crude product can be raised to l 75.5fl.7.7. by one recrystallization from chloroform ether, The product is identical in every respect with the product described in Example 2. I

"Concentration of the mother liquor yields some more of the pure product.

' EXAMPLE 12 13.65 g of 9-(3-methylimino-l-propenyl)-9,l0- dihydro-9,10-ethano-anthracene are suspended in 150 ml of methanol. solution of 4.0 g of sodium borohydride in 15 ml of water is added dropwise to this suspension whilst stirring and cooling with ice water. Whilst doing so, the temperature of the contents of the flask should not exceed 15C. In the course of the reaction, the Schiffs base rapdily dissolves. After 30 minutes, the reduction is complete. 200 ml of water are added and the mixture is extracted with three 100 ml portions of methylene chloride. The combined extracts are extracted by shaking with 50 ml of water, dried over anhydrous sodium sulphate and freed of the solvent in a water pump vacuum. 9-(3-Methylamino-lpropeny1)-9 l O-dihydro-9 ,1 O-ethano-anthracene of the formula CH, ITHCEL, c 1

is thus obtained as a colourless viscous oil which crystallises on standing (melting point 7880C).

The methanesulphonate of this compound is obmined as colourless crystals of melting point 168 "l71C, by neutralising an acetone solution of the base'with methanesulphonic acid.

After recrystallisation from isopropanol, the hydrochloride melts at 243244C.

EXAMPLE 13 The reaction sequence described in the two preceding examples can also be carried out in a one-pot process, as follows:

26.0 g of 9-( 3-0xo-1-propenyl)-9,l0-dihydro-9,l0- ethanoanthracene are converted into the Sehiffs base by means of gaseous methylamine, as described in Example 7. The resulting methanolic solution of the Schiffs base is thereafter reduced, whilst stirring and cooling with ice water, by dropwise addition of a solution of 4.0 g of sodium borohydride in 15 ml of water.

Working up takes place in the same manner as described in Example 8. 9-(3-Methylamino-l-propenyl)- 9,l0-dihydro-9,l0-ethano-anthracene of the formula CH2NHCH3 is obtained in the same yield, as a colourless oil. The

methanesulphonate prepared therefrom melts at l68l7lC and is identical in every respect with the product described in Example 12.

EXAMPLE 14 CH N'rlCr1 HCl is thus obtained as colourless crystals of melting point 240243C. After recrystallisation from isopropanol,

40 the hydrochloride melts at 243-244c. It is identical in every respect with the product of the same melting point described in British Patent 1,069,069.

EXAMPLE 1 5 5.46 g of the 9-(3-methylimino-l-propenyl)-9,l0- dihydro-9,lO-ethano-anthracene described in Example 7, of melting point l28l 29C, in 100 ml of fine spirit, are hydrogenated in a hydrogenation autoclave, in the presence of 1.0 g of Raney nickel (or 0.3 g of 10 percent strength palladium on charcoal) for 10 hours at 100C and 100 atmospheres gauge hydrogen pressure. After cooling, the catalyst is filtered off and half of the solvent is distilled off in vacuo. A 2N solution of hydrogen chloride in ethyl acetate is then added to the solution until it gives a slightly acid reaction. Hereupon, 9- (3-methyl-aminopropyl)-9, 10-dihydro-9, IO-ethanoanthracene hydrochloride of the formula and of melting point 2 1i,l 243C crystallises o ut.

Recrystallisation from isopropanol gives colourless EXAMPLE 1 6 13.0 g of 9-(3-oxo-l-propenyl)- 9,l-dihydro-9,l()- ethano-anthracene are shaken ina high pressure hydrogenation autoclave with I00 ml of isop'ropanol, 19.7 ml of 35 percent strength aqueous methylamine and 1 gof percent strength palladium on charcoal for 10 hours at 100C, under a hydrogen pressure of 100 'atmo spheres gauge. After cooling, and releasing the pressure, the catalyst is filtered of? and the filtrate is evaporated in vacuo. The residue is dissolved in ml of hot isopropanol and the solution is rendered slightly acid with a 3N solution of hydrogen chloride in ethyl acetate. 9-(3-Methylaminopro'pyl )-9, l O-dihydro-9, l O- ethano-anthracene hydrochloride of the formula cn mica Eel crystallises, after addition of 20 ml of ethyl acetate, in colourless prisms of melting point 243244C. The hydrochloride is identical, in every respect, with the hydrochloride of the same melting point described in Examples l4 and I5.

EXAMPLE 17 The 9( 3-methyliminol -propenyl )-9, l O-dihydro- 9,10-ethano-anthracene obtained in Example 14 is suspended in methanol, and reduced with an aqueous solution of sodium borohydride whilst cooling with ice, as in Example 8. 9-(3-Methylamino-l-propenyl)-9,l0- dihydro-9.l()-ethano-anthracene of the formula CH -NFlCH is thus obtained as a brownish amorphous mass.

The hydrochloride of the base is manufactured as follows:

The base is dissolved in a five-fold amount of acetone and neutralised by adding one equivalent of hydrogen chloride in ethyl acetate. Hereupon, the hydrochloride forms colourless crystals of melting point 24l243C. After recrystallisation from isopropanol-ether, the

melting point rises to 243244C. The hydrochloride is identical in every respect with the product described in Example I2.

-lliiCH is thus obtained as a yellowish oil which c'rystallises completely on "'trituration. The hydrochloride of the base is manufactured as follows:

The base is dissolved in a five-fold amount of acetone and neturalised by adding one equivalent of hydrogen chloride in ethyl acetate. Hereupon, the hydrochloride crystallises out in lemon-yellow needles of melting point 277279C. On recrystallisation from methanolethanol, the melting point rises to 284-286C.

EXAMPLE 19 12.35 g of 9-( 3-methylaminol -propenyl anthracene in l20 ml of toluene are heated to 200C in an autoclave. atmospheres gauge of ethylene are injected hot and the mixture is left to stand for 35 hours at a pressure of 75 atmopsheres gauge and a temperature of 200C. The brown solution is cooled, filtered through active charcoal and evaporated in vacuo. l-( 3- Methylaminol -propenyl )-9, l O-dihydro-9, l O-ethanoanthracene of the formula is thus obtained as a brownish amorphous mass.

The hydrochloride of the base is manufactured as in Example 5.

The hydrochloride forms slightly yellowish crystals of melting point 240242C. After recrystallisation from chloroform-isopropanol-ether, colourless crystals of melting point 243-244C are obtained. The hydrochloride is identical in every respect with the product described in Example 12.

What is claimed is:

1. Compounds of the formula in which n and m denote integers such that (n m) is not greater than 3, the radicals R which may be the same or different, each represents a radical selected from lowerr alkyl, lower alkoxy, lower alkenyloxy, lower alkylmercapto, lower alkylsulphonyl, nitro and trifluoromethyl radicals and halogen atoms, R denotes a hydrogen atom, a halogen atom or an alkyl radical and the symbols R,,, R,, and R,,", which may be the same or different, each represents a lower alkyl radical or ahydrogematom. r

A compound as claimed in claim 1 wherein R of the general formula represents lower alkyl, lower alkoxy,,,hydroxyl or trifluoromethyl groups or halogen 16 atoms and R, denotes a chlorine atom or a hydrogen atom.

3. Compounds as'claimed in claim 1 of the formula CH==CH-CHO (VII) wherein R, denotes a lower alkyl or lower alkoxy group, a trifluoromethyl group, a bromine or chlorine atomor a hydrogen atom, and is in the 2- or 3-position.

4. Compounds as claimed in claim 1 of the formula o en-cm 1 wherein R represents a methoxy group, a trifluoromethyl group, a chlorine atom or a hydrogen atom.

5. 3-(9-Antrhyl)-acrolein, or 3-[9-(2-chloro)- anthryl]-acrolein. v 

1. COMPOUNDS OF THE FORMULA
 2. A compound as claimed in claim 1 wherein RA of the general formula represents lower alkyl, lower alkoxy, hydroxyl or trifluoromethyl groups or halogen atoms and R10 denotes a chlorine atom or a hydrogen atom.
 3. Compounds as claimed in claim 1 of the formula
 4. Compounds as claimed in claim 1 of the formula
 5. 3-(9-Antrhyl)-acrolein, or 3-(9-(2-chloro)-anthryl)-acrolein. 